Numerous electrical instruments, such as oscilloscopes, recorders and the like, typically include control knobs to adjust operating parameters. In many instances, it is desirable for the efficient utilization space and economy of components to utilize control knobs which are capable of positional adjustment for controlling or varying an operating parameter and which can also be used to perform a switching operation, such as an "ON/OFF" switch. Such control knobs are typically angularly rotatable about a fixed axis and linearly movable along such axis, wherein the angular rotation is utilized to vary an operating parameter and the linear motion generally controls a switching feature. Examples of such control knobs would be an "ON/OFF volume" control knob typically found on a stereo receiver or an "ON/OFF-gain" control knob on a potentiometer or an "ON/OFF-trace position" control knob on a recording device. With many such electrical instruments, particularly electrical recording or monitoring instruments, it is desirable to lock the control knob in a specific position once a particular setting has been obtained.
With electronic components and equipment becoming smaller and more compact, there is a need for a lockable control knob which is small in size, yet provides positive locking and positioning of the control knob. It is likewise desirable to provide a control knob which is infinitely positionable and lockable in such positions. Locking control knobs known heretofore generally do not effectively or satisfactorily lend themselves to reduction in size in that many include components which are intricate and costly to manufacture in smaller sizes. Moreover, many control knobs known heretofore generally have limited angular adjustment and operate in stepped increments by detente arrangements or the like.
The present invention overcomes these shortcomings and provides a miniature locking control knob which may be set and locked in an infinite number of position settings and which is reliable, simple and relatively inexpensive.